Greenhorn

Former Oklahoma State star Marcus Smart may have seen his last playing time of the season with the Celtics. On Sunday Smart put up 20 points, 7 boards and 8 assists, but sprained his right thump while diving to the floor for a loose ball.

The Celtics are gathering more information on Smart regarding the severity of the injury and he’s getting a second opinion, but early returns are not promising. According to Mark Murphy of the Boston Herald, Boston thinks his return is far from guaranteed.

League source says Celtics don't know probability of Marcus Smart playing again this season. "(They're) waiting for that second opinion. Don't know if it's a 50 percent chance or a 30 percent chance. Just don't know."

As he was during his days in Stillwater, Smart is a key cog on defense. Nevermind his dreadful shooting numbers. His ability to switch on to multiple positions gives the Celtics a versatility they will desperately miss with him off the court. He’s averaging 10.2 points, 4.8 assists and 3.8 rebounds per game this season, all stats above his career averages.

And what makes the injury even complicated for Smart: he’s on a contract year. The Celtics and Smart failed to reach an agreement last fall, which means he’s due to become an restricted free agent this offseason. Although he’s proven to be fairly durable, a season-ending injury could hurt his chances of signing a mega-deal — and especially so with the Celtics, who will have the right to match any offer sheet a team signs him to after the season.